Wood chippers



Sept. 19, 1961 D. G. RICHES ETAL WOOD CHIPPERS Filed Feb. 24, 1960 INVENTOES' D E N I S GEORGE RICHES RAY JORGENSEN Mk4? W W 7 3,000,578 WOOD CHIPPERS Denis George Riches and Ray B. Jorgensen, Seattle, Wash, assignors to Sydney Hansel, Edmonds, Wash. Filed Feb. 24, 1960, Ser. No. 10,618 2 Claims. (Cl. 241-92) The invention relates to wood cutting machines having rotating knives which coact with a bed knife or anvil to cut chips from a log. These devices are commonly called chippers.

In existing machines, the coacting cutting elements become dulled through normal wear, or damaged as from steel or other foreign material entering the chipper. The wear and/or damage necessitates resharpening, or replacement, of one or more of these parts at intervals.

The objects of our invention are to reduce the cost of resharpening, to prolong the operating cycle between replacements, and to reduce the down time heretofore necessary to effect these operations. Further objects and advantages will appear as the disclosure proceeds.

We attain these objects by providing that the coacting cutting elements, and members ancillary thereto, are made in two interchangeable parts. A particular embodiment is described in the following specification and illustrated by the drawings in which:

FIGURE 1 is a fragmentary plan of the wood chipper.

FIGURE 2 is an enlarged section taken on the line 22 of FIGURE 1.

FIGURE 3 is an elevation of a two part knife and clamp secured to the rotary disc.

FIGURE 4 is a plan of a twopart anvil.

In the drawings like characters of reference indicate corresponding parts in each figure.

The numeral indicates generally a chipper having a base 11 on which a motor driven shaft 12 is journalled. A vertically disposed rotary disc 14 is mounted upon the shaft 12 and is partly enclosed within a casing 15. Extending through the rotary disc are a plurality of slots 16 and secured to the working face 17 of the disc adjacent to each slot is a knife 18.

Each knife 18 is supported upon a holder 20 which is secured to the disc 14 by bolts 21 and said holder is fitted with a counter knife 22. The cutting edge 24 of the knife 18 is projected beyond the working face 17 of the rotary disc a distance determined by the thickness of a spacer block 25, and a clamp 26 is secured to said knife and disc by suitably spaced bolts 27. The knife 18 and its clamp 26 are divided longitudinally into two parts. The spacing of the bolts 27 is such that the knife 18A and clamp 26A may be interchanged with parts 18B and 26B, if desired.

Mounted upon the base 11 is a feed spout 30 which may be a substantially rectangular structure disposed at any suitable angle to the working face 17 of the disc 14. The feed spout has spaced side walls 31, an inclined rear wall 32 and a bottom wall 33. Aligned openings 37 are formed in the bottom wall 33 of the feed spout and extending through said openings into the base 11 are bolts 38 which are of a size to permit the spout to be adjusted towards and away from the face 17 of the disc 14. The underside of the bottom wall 33 is provided with a rebate 40 and housed within said rebate is a bed knife or anvil 42.

nitc States Patent "ice The anvil 42 is a fiat rectangular member with its side edges being beveled to provide inclined faces 43 and vertical faces 44, see particularly FIGURE 2, and said faces are suitably hardened to olfer greater resistance to wear. As in the case of the knife 18, the anvil 42 is divided into two parts 42A and 42B and said parts are separately secured to the wall 33 of the feed spout by spaced bolts 46. The bolts 46 extend through enlarged openings 47 formed in the anvil 42 which is positioned so that a face 43 is disposed in the same plane as the inner surface of the inclined rear wall 32 of the feed spout. Appropriately sized shims 48 are interposed between the anvil 42 and the rear edge of the rebate 40 to enable the anvil to be positioned correctly with respect to the inclined wall 32.

A log to be cut into pulp chips is entered into the feed spout 30 and moves therethrough into contact with the working face 17 of the disc 14. The knives 18 carried by the rotating disc slice off chips from the end of the log and the chips are carried through the slots 16 to discharge. It has been found that, over an extended period of operation, a point of greatest wear will develop on the knives 18 and the anvil 42 particularly when the logs being fed to the chipper are all substantially of the same size and shape. For example the cutting edge 24 of a knife 18A may wear in the area 50 shown in dotted line in FIGURE 3. In these circumstances, the positions of the knife 18A and clamp 26A are interchanged with the adjoining parts 18B and 26B and this will enable the chipper to be run until wear and/or damage again develops. It is to be understood that either knives, or clamps, or both, may be interchanged according to necessity. Alternatively, if time permits knife 18A and its clamp 26A are removed from the disc 14 and the cutting edge of the knife ground to remove the area 50, whereupon the parts are replaced upon the disc.

Local wear similarly may appear as for example on 42A of the anvil. The feed spout 30 may then be removed from the base 11 and the worn part of the anvil is unbolted from the bottom wall 33 of said spout. The anvil part 42Ais positioned in the rebate 40 so as to pre sent an unworn face 43 to the cutting edges 24 of the knives 18 and is again secured in position by means of the bolts 46. If desired, this repositioning of the anvil part may be repeated as required until all the inclined faces 43 exhibit signs of wear at which time the part 42A may be interchanged with the part 42B and the chip cutting operation continued.

When it is finally necessary to sharpen the bed knife or anvil 42 the inclined faces 43 are ground down to remove the worn areas and the vertical faces 44 are also subjected to grinding to remove an equivalent amount of metal therefrom. The resharpened anvil will enable the wood chipper to be run for another lengthy period with periodic shut downs for changing the position of one or both of the anvil parts.

Thus, in a chipping machine constructed according to our invention, the amount of grinding to effect one resharpening is reduced, the interval between replacements is prolonged, the total non-operating time is reduced, and a smaller inventory of replacement parts is required.

We have described a chipper in which specific elements are made in two parts and, in the drawings, these two parts are shown as being of the same size. The two parts may be of unequal size and, as well, for certain applications and capacities, the number of such parts may exceed two, and either be of the same or of different size. We have described and illustrated a drop feed chipper, obviously the invention is applicable to chippers having horizontal or other feed.

What we claim as our invention is:

1. In a chipper having a base, a rotary disc normal to the base, chip cutting knives projecting from the working face of the disc, a log feed spout supported on the base and having a bottom wall and a rear wall inclined at an acute angle to the disc working face, said bottom wall having a rebate on its underside adjacent to the working face of the disc, an anvil within the rebate, said anvil having parallel side edges, each of said side edges being beveled to provide upper and lower wear faces, said Wear faces being inclined at substantially the same angle as the inclined rear wall of the feed spout, said anvil being divid- 4 ed longitudinally into a plurality of identical and interchangeable parts, and means for adjustably securing each anvil part to the bottom wall of the feed spout.

2. In a chipper as claimed in claim 1, and means for adjusting the feed spout towards and away from the chipper knives.

References Cited in the file of this patent UNITED STATES PATENTS 658,218 McAllister Sept. 18, 1900 733,691 Baker July 14, 1903 1,228,247 Ross May 29, 1917 1,464,690 Andrews Aug. 14, 1923 2,322,306 McLaren June 22, 1943 FOREIGN PATENTS 194,553 Germany Ian. 23, 1908 602,693 Germany Sept. 14, 1934 

